HRT Barrier

So I have wanted to begin HRT for a while now, but there is a huge barrier, that is making it so hard for me. That barrier is my parents. To be able to begin HRT I would have to talk with my parents and get appointments scheduled and all of that. Like I know that my parents accept me, no matter what, they have said it multiple times, (Hell I've made a little trans flag in my room so they probably already know) but there is still the barrier of talking to my parents to actually be able to begin HRT.

And another small-ish barrier is my grandmother, because she is right wing, and pretty transphobic, but I have a really solid relationship with her despite that, but I am scared that, said relationship would be strained, but overall this is a smaller, less terrifying barrier.

I need advice on what to do.

PS: I am 18yo pre everything